CVE-2021-45098

An issue was discovered in Suricata before 6.0.4. It is possible to bypass/evade any HTTP-based signature by faking an RST TCP packet with random TCP options of the md5header from the client side. After the three-way handshake, it's possible to inject an RST ACK with a random TCP md5header option. Then, the client can send an HTTP GET request with a forbidden URL. The server will ignore the RST ACK and send the response HTTP packet for the client's request. These packets will not trigger a Suricata reject action.

CVSS v3.1

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVSS v2.0

5.0 MEDIUMAV:N/AC:L/Au:N/C:N/I:P/A:N

EPSS

1.82% chance of exploitation in the next 30 days, 77th percentile

Published

2021-12-16

Updated

2025-11-03

Proof-of-concept exploits (1)

• https://redmine.openinfosecfoundation.org/issues/4710

References

• CVE Record
• NVD entry

Related

• CVE-2021-45092
• CVE-2021-45099
• CVE-2021-45088
• CVE-2021-45105
• CVE-2021-45087
• CVE-2021-45117